Simultaneous programmed temperature GLC assay of phenol, chloroxylenol, and lidocaine hydrochloride in topical antiseptic cream.

A simultaneous programmed temperature GLC assay for the active ingredients in a topical antiseptic cream is described. The sample is extracted directly using a dimethyl sulfoxide solution of p-cresol, 4-chlorophenol, and 2-amino-4-phenylthiazole as internal standards for phenol, chloroxylenol, and lidocaine hydrochloride, respectively. The resulting solution is chromatographed by temperature programming on an OV-225 column from 90 to 225 degrees. The internal standard calculation is accomplished using peak heights or peak areas. The relative standard deviation of all assays is less than 2%.